To assign this material to the sword, select when done and drag and drop the material slot on the object.

It may be that some faces of the object have a ID material different from 1, in this case, to clean the ID, select all model in Element mode, enter value 1 in material ID (Surface Properties roll out).

All the faces have now the ID 1

Create a material checker with Tile of 20 for example.

Then with Drag and Drop it with into ID 2 in Instance mode.

This material will use to adjust the UV of all the sword and it will be copied each time as an instance, one can thus easily change Tile for all with the original material

The ID 2 will be the material of the blade.

in polygon mode select all the faces of the blade

Enter Material ID value 2.

The selected faces change color, the checkerwork does not appear because UV are not defined. (do not forget to activate the posting of textures in the material checkerwork).

Always in sub-object mode with the faces selected in Editable Mesh, apply a planar UVW Map

For direct Gizmo of mapping correctly, use View Align in View Face, Center and the FIT to fix it on the selection of
faces.

Finally the board of texture will be square with equal values in Length and Width.

Here you do not need to improve UV.

In the stack, right click on the UVW Map, and select Collapse To to simplify it.

Thus helps with memory speed.
Meshsmooth remains on top and one does not lose the adjustments on Creases or Weights.

Return to Editable Poly in Polygon mode, benefit from the still active selection to hide the faces already textured with Hide.

By making this operation after each UVW Map, it becomes increasingly simple to select the not yet textured faces.

In Material Editor, copy the checker into ID 3

Select the corresponding faces as shown then apply Material ID 3.

As previously, apply to these faces a planar UVW Map, then enter the same values in Width and Length to have a coherent mapping with that of the blade, proceed as before.

select the faces opposite and apply the checker ID 4.

Another planar UVW then 'collapse to' the stack

Click on Meshsmooth, you can see that the higher density mesh still maintains the correct mapping

To still improve one thing, activate Materials in Surface Parameters, that smooths according to materials.

There are thus clearer and better smoothed material limits.

As before, click on UVW Map and Collapse To.

Note that one you can temporarily suspend the effect of a modifier while clicking on the icon bulb next to it.